Read both passages and the 12 statements. Decide if each statement is supported by
* Passage A
* Passage B
* Both Passages
* Neither Passage
Passage A
Hanging clear, water-filled bags from doorways is an increasingly popular, and rather unlikely, new method for deflecting annoying —and potentially disease-carrying-flies from building entrances.
Some advocates claim that the flies recognize the liquid as the surface of a body of water while others— ludicrously-insist the insect flies away because it is frightened by its own magnified reflection. The most credible explanation, however, concerns the refraction of light.

Light rays travel in a straight line. Refraction is what happens when something —like a clear object such as a piece of glass or a bag of water-gets in the way.
Hitting the object changes the ray's velocity and direction, bending, or refracting, it. Refracted rays of light can cause optical illusions, including such things as mirages that even confuse human eyes.
A fly's head consists primarily of a pair of large complex eyes, each composed of 3,000 to 6,000 simple eyes. This physiology allows the fly to see in multiple directions at once. Even though these eyes cannot move or focus on objects like human eyes, they grant the fly a mosaic view of its surroundings, and each simple eye provides one small piece of the puzzle. A housefly bases its sense of direction on the direction sunlight comes from, so when these complex, sensitive eyes experience refracted light, the fly becomes confused and flies away.
Although this explanation is persuasive and plausible, research conducted to replicate the results on fly-plagued poultry farms has been inconclusive.
Passage B

While the water-bag method of fly repellent has many supporters, it has at least as many detractors.
Advocates claim that refracted light in water baffles the flies' compound eyes. This theory seems quite plausible, but critics classify it as a kind of coincidence masquerading as cause and effect. They say that hanging water bags may seem to work due to the placebo effect. In medicine this is a treatment without therapeutic value, which is administered as if it were a therapy. The "medicine" makes people feel better due to psychological effects rather than due to its curative values. The same effect is likely to occur when people think they are treating a pest problem, and thus notice that the problem seems to diminish.
But what if the placebo even increases the problem?
Recently, scientists conducted an experiment over the course of thirteen weeks on two egg farms to measure fly activity and encountered just such a situation. They installed commercial, water-based optical fly repellents and concluded that the areas equipped with water bags actually attracted more of these irritating creatures.


1. The passage mentions experiments conducted in an agricultural environment.
2. The passage makes a convincing case for the effectiveness of the water-bag method.
3. The passage states that there are more people who do not believe in the water-bag theory than there are supporters of the theory.
4. The passage suggests that people hang water bags and then notice fewer pests.
5. The author supports the theory that flies are scared of their own reflection.
6. The passage mentions the claim that water bags make flies look bigger.
7. The passage mentions the fact that flies have compound eyes.
8. The passage states that use of water bags is connected to higher levels of fly activity.
9. The passage claims that refracted light can affect human optical perceptions.
10. The passage mentions the claim that refracted light in water confuses flies.
11. The author of the passage dismisses the water-bag method as ineffective.
12. The author of the passage cites human beliefs as an explanation.